MODULE FRAMEWORK AND ASSESSMENT SHEET

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2 MODULE FRAMEWORK AND ASSESSMENT SHEET LEARNING OUTCOMES (LOS) ASSESSMENT STANDARDS (ASS) FORMATIVE ASSESSMENT ASs Pages and (mark out of 4) LOs (ave. out of 4) SUMMATIVE ASSESSMENT Tasks or tests Ave for LO (%) (% and mark out of 4) LO 1 We know this when the learner: NUMBERS, OPERATIONS AND RELATIONSHIPS The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems. 1.3 solves problems in context including contexts that may be used to build awareness of other learning areas, as well as human rights, social, economic and environmental issues such as: measurements in Natural Sciences and Technology contexts. LO 3 We know this when the learner: SPACE AND SHAPE (GEOMETRY) The learner will be able to describe and represent characteristics and relationships between two-dimensional shapes and three dimensional objects in a variety of orientations and positions. 3.2 in contexts that include those that may be used to build awareness of social, cultural and environmental issues, describes the interrelationships of the properties of geometric figures and solids with justification, including: transformations.

3 LEARNING OUTCOMES (LOS) ASSESSMENT STANDARDS (ASS) FORMATIVE ASSESSMENT ASs Pages and (mark out of 4) LOs (ave. out of 4) SUMMATIVE ASSESSMENT Tasks or tests Ave for LO (%) (% and mark out of 4) 3.3 uses geometry of straight lines and triangles to solve problems and to justify relationships in geometric figures; 3.4 draws and/or constructs geometric figures and makes models of solids in order to investigate and compare their properties and model situations in the environment; 3.6 recognises and describes geometric solids in terms of perspective, including simple perspective drawing; 3.7 uses various representational systems to describe position and movement between positions, including: ordered grids. LO 4 We know this when the learner: MEASUREMENT The learner will be able to use appropriate measuring units, instruments and formulae in a variety of contexts. 4.4 uses the theorem of Pythagoras to solve problems involving missing lengths in known geometric figures and solids.

4 CONTENTS LEARNING UNIT 1 Quadrilaterals Characteristics of various quadrilaterals... 2 days Defining and classifying various quadrilaterals... 2 days Calculating areas... 3 days Applying the characteristics of quadrilaterals in simple problems in geometry... 3 days LEARNING UNIT 2 Perspective drawing Projections... 5 days orthographic isometric one-point perspective LEARNING UNIT 3 Transformations Reflection...1 day Rotation...1 day Translation...1 day Symmetry...1 day Combining to... 3 days generate novel patterns tessellate Coordinate references... 2 days

5 LEARNING UNIT 1... ACTIVITY 1.1 To explore and identify the characteristics of some quadrilaterals LO 3.4 In this work, you will learn more about some very important quadrilaterals. We need to know their characteristics as they occur often in the natural world, but especially in the manmade environment. You will have to measure the lengths of lines and the sizes of angles, so you will need to have your ruler and protractor ready. For cutting out quadrilaterals you will need a pair of scissors. First we start with the word quadrilateral. A quadrilateral is a flat shape with four straight sides, and, therefore four corners. We will study the sides (often in opposite pairs), the internal angles (also sometimes in opposite pairs), the diagonal lines and the lines of symmetry. Look out for new words, and make sure that you understand their exact meaning before you continue. 1. Lines of symmetry You have already encountered the quadrilateral we call a square. 1.1 The square From your sheet of shapes, cut out the quadrilateral labelled SQUARE. Fold it carefully so that you can determine whether it has any lines of symmetry. Lines of symmetry are lines along which any shape can be folded so that the two parts fall exactly over each other. Make sure that you have found all the different lines of symmetry. Then mark the lines of symmetry as dotted lines on the sketch of the square alongside, using a ruler. One of them has been done as an example. The dotted line in the sketch is also a diagonal, as it runs from one vertex (corner) to the opposite vertex. - Look around you in the room. Can you find a square shape quickly? If we push the square sideways, without changing its size, it turns into a rhombus. 1.2 The rhombus Identify the RHOMBUS from the sheet of shapes. It is clear that it looks just like a square that is leaning over. Cut it out so that you can fold it to find its lines of symmetry. Again, draw dotted lines of symmetry on this diagram - Is the dotted line in this sketch a line of symmetry? If we take a rhombus and stretch it sideways, then a parallelogram is produced.

6 1.3 The parallelogram Find the PARALLELOGRAM on the sheet of shapes. Cut it out so that you can fold it to find any lines of symmetry; draw them as dotted lines. - You might have to search a bit to find something in the shape of a parallelogram. Your homework is to see whether you can find one in 24 hours. This parallelogram turns into a rectangle when we push it upright. 1.4 The rectangle Cut out the RECTANGLE and find its lines of symmetry to fill in on the rectangle alongside. - Write down the differences you see between the rectangle and the square. Now take the two end sides of the rectangle and turn them out in different directions to form a trapezium. 1.5 The trapezium There is more than one TRAPEZIUM on the shape sheet. This is another example of a trapezium. Again, cut them out and find lines of symmetry. - Using all the different kinds of trapezium as a guide, write down in words how you will recognise the shape. 1.6 On the shape sheet you will find two kinds of KITE. Cut out both kinds and find any lines of symmetry.

7 Is there a special name for the dotted line in one of the kites above? Did you work correctly in this section? Neatness and accuracy 2. Side lengths Study the examples of the six types of quadrilateral. First measure the sides of each as accurately as you can, to see whether any of the sides are the same length, and mark them. In this sketch of a parallelogram, the opposite sides have been marked with little lines to show which sides have equal lengths. - Is a rhombus just a parallelogram with all four sides equal? 3. Parallel sides Parallel lines (as you know) are lines that always stay equally far from each other. This means that they will never meet, no matter how far you extend them. They need not be the same length. You already know how to mark parallel lines with little arrows to show which are parallel. Now study your quadrilaterals again to see whether you can identify the parallel lines with a bit of measuring. This is not easy, but you will do well if you concentrate and work methodically. - If you could change just one side of any trapezium, could you turn it into a parallelogram? What would you have to change? 4. Internal angle sizes It is easy to measure the internal angles with your protractor. Write the sizes in on the sketch, and then see whether you find right angles or equal angles. You can mark equal angles with lines to show which are which, as in this sketch of the parallelogram. - Add up all the internal angles of every quadrilateral you measured and write the answer next to the quadrilateral. Does the answer surprise you?

8 5. Diagonals Diagonals run from one internal vertex to the opposite vertex. Draw the diagonals in all the quadrilaterals (sometimes they will be on top of the lines of symmetry). Measure the lengths of the diagonals to identify those quadrilaterals where the two diagonals are the same length. Mark them if they are the same, just as you marked the equal sides. Use your protractor to carefully measure the two angles that the diagonals make where they cross (intersect). Take note of those quadrilaterals where the diagonals cross at right angles. The diagonals also divide the internal angles of the quadrilateral. Measure these angles and make a note of those cases where the internal angle is bisected (halved) by the diagonal. Quality of answers Poor Unsatisfactory Satisfactory Excellent Not done yes only Reason Fuller discussion 3 Not done side only Explanation given 4 Not done Answer, but wrong 360 Explains why two sides change Mentions division into 2 s 5 Not done Some done Almost all done Perfect 6. Tabulate your results Complete the following table to summarise your results for all the characteristics of all the quadrilaterals. Think very carefully about whether what you have observed is true for all versions of the same shape. For example, you may find that the two diagonals of a certain trapezium are equal; but would they be equal for all trapeziums? And if a kite has two equal diagonals, is it correct to call it a kite? This table contains very useful information. Make sure your table is correct, and keep it for the following exercises.

9 Square Rhombus Parallelogram Rectangle Trapezium Kite Number of lines of symmetry All sides equal 2 pairs of opposite sides equal 2 pairs of adjacent sides equal 2 pairs of parallel sides Only 1 pair of parallel sides No parallel sides All internal angles equal 2 pairs of opposite internal angles equal Only 1 pair of opposite angles equal Diagonals always equal Diagonals are perpendicular Both diagonals bisect internal angles Only one diagonal bisects internal angles Both diagonals bisect area Only one diagonal bisects area Diagonals bisect each other LO 3.4

10 ... ACTIVITY 1.2 To compare quadrilaterals for similarities and differences LO Comparisons For the next exercise you can form small groups. You are given pairs of quadrilaterals, which you have to compare. Write down in which ways they are alike and in which ways they are different. If you can say exactly by what process you can change the one into the other, then that will show that you have really understood them. For example, look at the question on parallel sides at the end of section 3 above. Each group should work with at least one pair of shapes. When you work with a kite, you should consider both versions of the kite. Rhombus and square Trapezium and parallelogram Square and rectangle Kite and rhombus Parallelogram and kite Rectangle and trapezium If, in addition, you would like to compare a different pair of quadrilaterals, please do so! How well did you cooperate with the group? Paid attention during group discussions Was careful not to obstruct others efforts Responded helpfully when asked Asked questions when necessary Listened attentively to other group members Poor Unsatisfactory Satisfactory Excellent Helped resolve conflicts

11 1. Definitions A very short, but accurate, description of a quadrilateral using the following characteristics, is a definition. This definition is unambiguous, meaning that it applies to one shape and one shape only, and we can use it to distinguish between the different types of quadrilateral. The definitions are given in a certain order because the later definitions refer to the previous definitions, to make them shorter and easier to understand. There is more than one set of definitions, and this is one of them. A quadrilateral is a plane (flat) figure bounded by four straight lines called sides. A kite is a quadrilateral with two pairs of equal adjacent sides. A trapezium is a quadrilateral with one pair of parallel opposite sides. A parallelogram is a quadrilateral with two pairs of parallel opposite sides. A rhombus is a parallelogram with equal adjacent sides. A square is a rhombus with four equal internal angles. A rectangle is a parallelogram with four equal internal angles. LO ACTIVITY 1.3 To develop formulas for the area of quadrilaterals intuitively LO 3.4 Calculating areas of plane shapes. Firstly, we will work with the areas of triangles. Most of you know the words half base times height. This is the formula for the area of a triangle, where we use A for the area, h for the height and b for the base. Area = ½ base height; A = ½ bh; A = are various forms of the formula. But what is the base? And what is the height? The important point is that the height and the base make up a pair: the base is not any old side, and the height is not any old line.

12 The height is a line that is perpendicular to the side that you choose as the base. Refer to the sketches above. The base and its corresponding height are drawn as darker lines. Below are three more examples showing the base/height pairs. Take two other colours, and in each of the above six triangles draw in the two other matching pairs of base/height, each pair in its own colour. Then do the following exercise: Pick one of the triangles above, and calculate its area three times. Measure the lengths with your ruler, each time using another base/height pair. Do you find that answers agree closely? If they don t, measure more carefully and try again. Accuracy The height is often a line drawn inside the triangle. This is the case in four of the six triangles above. But if the triangle is right-angled, the height can be one of the sides. This can be seen in the fourth triangle. In the sixth triangle you can see that the height line needs to be drawn outside the triangle. SUMMARY: In summary, if you want to use the area formula you need to have a base and a height that make a pair, and you must have (or be able to calculate) their lengths. In some of the following problems, you will have to calculate the area of a triangle on the way to an answer. Here is a reminder of the Theorem of Pythagoras; it applies only to right-angled triangles, but you will encounter many of those from now on.

13 I! If you are a bit vague about applying the theorem, go back to the work you did on it before and refresh your memory. Using the formula, calculate the area of ABC where A = 90, BC = 10 cm and AC = 8 cm. A reasonably accurate sketch will be helpful. This is a two-step problem: first use Pythagoras and then the area formula. When calculating the area of quadrilaterals, the same principle applies as with triangles: when we refer to height it is always with reference to a specific base. We can use the formula for a triangle s area to develop some formulae for our six quadrilaterals. A square consists of two identical triangles, as in the sketch. Let us call the length of the square s side s. Then the area (A) of the square is: A = 2 area of 1 triangle = 2 (½ base height) = 2 ½ s s = s 2 = side squared. You probably knew this already! It works the same for the rectangle: The rectangle is b broad and l long, and its area (A) is: A = first triangle + second triangle = (½ base height) + (½ base height) = (½ b ) + (½ b) = ½ b + ½ b = b = breadth times length. You probably knew this already! The parallelogram is a little harder, but the sketch should help you understand it. If we divide it into two triangles, then we could give them the same size base (the long side of the parallelogram in each case). If we call this line the base of the parallelogram, we can use the letter b. You will see that the heights (h) of the two triangles are also drawn (remember a height must be perpendicular to a base). Can you convince yourself (maybe by measuring) that the two heights are identical? And what about the two bases? The area is: A = triangle + triangle = ½ bh + ½ bh = bh = base times height. A challenge for you: Do the same for the rhombus. (Answer: A = bh, like the parallelogram).

14 Let s see what we can do to find a formula for the trapezium. It is different from the parallelogram, as its two parallel sides are NOT the same length. Let us call them Ps 1 and Ps 2. Again, the two heights are identical. Then from the two triangles in the sketch we can write down the area: A = triangle1 + triangle2 = ½ Ps1 h + ½ Ps2 h = ½ h (Ps1 + Ps2) = half height times sum of parallel sides. (Did you notice the factorising?) Finally, we come to the kite, which has one long diagonal (which is the symmetry line) and one short diagonal, which we can call sl (symmetry line) and sd (short diagonal). The kite can be divided into two identical triangles along the symmetry line. Because a kite has perpendicular diagonals, we know that we can apply the formula for the area of a triangle easily. This means that the height of the triangles is exactly half of the short diagonal. h = ½ sd. Look out in the algebra below where we change h to ½ sd! Both sorts of kite work the same way, and give the same formula. Refer to the sketches. Area = 2 identical triangles = 2( ½ sl h) = 2 ½ sl ½ sd = sl ½ sd = ½ sl sd = half long diagonal times short diagonal. In the following exercise the questions start easy but become harder you have to remember Pythagoras theorem when you work with right angles. Calculate the areas of the following quadrilaterals: 1 A square with side length 13 cm 2 A square with a diagonal of 13 cm (first use Pythagoras) 3 A rectangle with length 5 cm and width 6,5 cm 4 A rectangle with length 12 cm and diagonal 13 cm (Pythagoras) 5 A parallelogram with height 4 cm and base length 9 cm 6 A parallelogram with height 2,3 cm and base length 7,2 cm 7 A rhombus with sides 5 cm and height 3,5 cm

15 8 A rhombus with diagonals 11 cm and 12 cm (What fact do you know about the diagonals of a rhombus?) 9 A trapezium with the two parallel sides 18 cm and 23 cm that are 7,5 cm apart 10 A kite with diagonals 25 cm and 17 cm Problem At most one step correct Few steps correct Most steps correct No errors LO 3.4

16 ... ACTIVITY 1.4 To apply understanding of quadrilaterals and their properties in problems LO 3.7 LO 4.4 All the figures for this section are on a separate problem sheet. Use it together with the questions that follow here. Work in pairs as follows: first study each problem independently until you have solved it or gone as far as you can. Then explain your solution carefully, and step by step, to your partner, until he understands it well enough to write it down. In the following problem it will be your partner s turn to explain his solution to you for writing down. You should remember to give a reason or explanation for everything you do. 1. Calculate the values of a, b, c, etc. from the information given here and in the sketch, and answer the question. 1.1 The diagram shows a square with one side 3 cm. a = an adjacent side. b = the diagonal. c = the area of the square. Why does the diagonal make a 45 angle with the side? 1.2 A rhombus is given, with long diagonal = 8 cm and short diagonal = 6 cm. a = side length. b = area of rhombus.. Why are you allowed to use the Theorem of Pythagoras here? 1.3 The diagram shows a rectangle with a short side = 5 cm and a diagonal = 13cm. a = the long side. b = area of rectangle. Why is the other diagonal also 13 cm? 1.4 The figure is a parallelogram with one internal angle = 65, height = 3 cm and long side = 9 cm. a = smaller of internal angles. b = larger of internal angles. c = area of parallelogram Explain why this parallelogram has the same area as a 3 cm by 9 cm rectangle. 2. Calculate the value of x from the information in the sketches. 2.1 An equilateral triangle is given, with side 15 cm and area = 45 cm 2. x = height of triangle. Why does this triangle have a 60 internal angle?

17 2.2 The diagram shows a trapezium with longest side 23 cm and the side parallel to it 15 cm and height = 8 cm. x = area of trapezium. Why are the two marked internal angles supplementary? 2.3 The figure is a kite with area 162 cm 2 and a short diagonal of 12 cm. x = long diagonal. Why do the internal angles of the kite add up to 360? 2.4 The sketch shows the kite from question 2.3 divided into 3 triangles with equal areas (ignore the dotted line). x = top part of long diagonal. 3. These problems require you to make equations from the information in the sketch, using your knowledge of the characteristics of the figure. Solving the equations gives you the value of x. 3.1 The figure is a rhombus with two angles marked 3x and x respectively. Why can t we call this figure a square? 3.2 In the parallelogram, two opposite angles are marked x + 30 and 2x 10 respectively. Explain why the marked angle is The trapezium shows the two marked angles with sizes x 20 and x + 40 respectively. Why is this not a parallelogram? 3.4 Given is a rhombus with the short diagonal drawn; one angle made by the diagonal is 50 and one internal angle of the rhombus is marked x. LO 3.7 LO 4.4

18 L EARNING UNIT 1 Quadrilaterals ASSESSMENT I can... ASS NOW I HAVE TO... identify quadrilateral types 3.4 tabulate characteristics of quadrilaterals 3.4 contrast quadrilaterals 3.4 calculate areas of quadrilaterals 3.3; 4.4 apply properties of quadrilaterals in problems 3.3; 4.4 good partly not good For this learning unit I... Worked very hard yes no Did not do my best yes no Did very little work yes no Date: Learner can... ASS comments identify quadrilateral types tabulate characteristics of quadrilaterals contrast quadrilaterals calculate areas of quadrilaterals 3.3; apply properties of quadrilaterals in problems 3.3; CRITICAL OUTCOMES Works cooperatively in group Communicates logically and factually Folds and measures accurately Uses given information for creative synthesis of answer Educator: Signature: Date: Feedback from parents: Signature: Date:

19 SHAPE SHEET FOR LEARNING UNIT 1

20 PROBLEM SHEET FOR LEARNING UNIT 1

21 Putting three dimensions into two LEARNING UNIT 2... ACTIVITY 2.1 To draw plan and side views of three-dimensional objects to scale ORTHOGRAPHIC PROJECTION LO 1.3 LO 3.4 On the squared paper below you can see three drawings, each showing one side of a square wooden block with shaped holes in it. These are three orthographic views of the object. The drawings are done from the viewpoint of someone who is looking at the exact centre of each side of the block, with the line of sight perpendicular to the side. Ortho refers to 90. If each square on the paper represents 1 cm, calculate the outside dimensions of the block. Then calculate the total volume of wood removed in the making of the three different holes in the block. These drawings give the dimensions of the object accurately to scale. This makes it possible for someone who has to manufacture or construct the object, to do it accurately. Architects use orthographic projections to make drawings of the plan of a building, as well as the views from the front and the sides. A builder needs to submit these drawings, as well as other technical specifications, to the people responsible for giving him permission to continue with the building. Draw, as accurately as you can, the plan of your family s house. If you can, also draw the front view of the house. Remember that you have to decide how many metres in the actual house will be represented by each centimetre in your drawing; this is the scale of your drawing. How well did you do the two questions?

22 ... ACTIVITY 2.2 To understand what the meaning and application of perspective drawings are LO 3.4 ISOMETRIC PROJECTION Alongside is a three-dimensional drawing of the same block. You can read the dimensions of the object from the drawing, just as in the orthographic drawings above, because iso refers to the same and metric refers to measurement. An isometric drawing is very useful, but it is not a good picture of what we would really see if we had the block in front of our eyes. To give a more realistic view of the object, we have to make a perspective drawing. This is discussed in the next section. Here is some isometric paper for you to use. Take one of your fat textbooks and draw an isometric projection of it. First determine a good scale for your drawing.

23 Did you make a good isometric drawing? LO ACTIVITY 2.3 To understand what the meaning and application of perspective drawings are LO 3.6 ONE-POINT PERSPECTIVE PROJECTION This is how you can make a perspective drawing on a window (use a marker pen that will wash off the glass when you have done, or stick transparent tracing paper to the glass). On the other side of the glass you have the object you want to draw say you put a box on a table so that you can see it clearly fitting into the whole pane of glass. Don t put the box perpendicular to the window, but put it with one corner facing forward. It is essential that you keep your head absolutely still while you work. Copy on the glass exactly what you see through the window, especially the edges of the box. You can compare your work with the explanation below, to see whether you have managed it well. Of course, this is not what an architect does when he has to draw a picture of a building that still has to be built! He gives the orthographic projections that he has drawn to a draughtsperson who uses mathematical principles to make a perspective drawing of it. There are one-point, two-point and three-point perspective drawings. This refers to the number of vanishing points in the drawing.

24 Here is a simple sketch in one-point perspective of a landscape with a railway line and a fence. There is one point on the horizon where all the lines in the sketch seem to meet and vanish. In the sketch the railway sleepers, as well as the fence posts, seem to get closer to each other as they vanish into the distance; but we know that they are evenly spaced everywhere. The railway lines seem to get closer to each other as we move our eyes to the horizon. The distances between the sleepers, and between the fence posts, diminish in proportion to how far they are away from you. These effects create the illusion of three dimensions, even though the sketch is in two dimensions on a flat sheet of paper. The next drawing is a perspective drawing of the square block that this section started with. As you can see, this shows a more realistic view of what the block really looks like in real life. The dotted lines show the horizon and the vanishing point. The artist and architect Filippo Brunelleschi discovered how to use one-point perspective in the beginning of the fifteenth century. Attempt to draw a one-point perspective drawing of the block from the face of the block you can t see in this drawing. LO 3.6

25 L EARNING UNIT 2 Perspective drawing ASSESSMENT I can... ASS NOW I HAVE TO... describe orthographic projection drawings make an orthographic projection drawing 3.4 understand isometric projections 3.4 make an isometric projection 3.4 understand the use of perspective drawing 3.6 good partly not good For this learning unit I... worked very hard yes no did not do my best yes no did very little work yes no Date: Learner can... ASS comments describe orthographic projection drawings make an orthographic projection drawing understand isometric projections make an isometric projection understand the use of perspective drawing CRITICAL OUTCOMES Understands role of mathematics in draughtsmanship Draws accurately to specification Reads drawings for the purposes of calculating volumes Develops spatial awareness Educator: Signature: Date: Feedback from parents: Signature: Date:

26 LEARNING UNIT 3 Having fun with plane shapes... ACTIVITY 3.1 To understand and use the principle of translation, learning suitable notations LO 3.2 LO 3.7 TRANSFORMATION THROUGH TRANSLATION Above we have the first quadrant of a Cartesian plane. There are ten plane figures to be seen. If you imagine that you cut out the shaded shapes above, and then move them to new positions (unshaded) by sliding them across the page, then you have translated them. Notice that they stay upright (they don t change their orientation). These shapes have been transformed through translation. Write down the names of the five shapes. If you label the vertices of the shape, then the new position has similar (but not the same) labels. You can see this on the rectangle above. From now on, you will use the same system of labels in your work. In the rectangle, position A moves to position A, B to B, etc. We have different ways of describing translations. This is like giving someone instructions so that they can produce the result you want. 1. For instance, if I say, Move the oval shape 4½ units right and 3 units down, this gives the new position of the oval. Describe the new position of the pentagon in the same way in words. 2. Translating the square: Square ABCD square A B C D means map square ABCD onto square A B C D. This is better said by specifying the positions: A (1 ; 9) A (5 ; 8) and B(4 ; 9) B (8 ; 8), etc. Use the coordinate mapping system to describe the translation of the triangle. Label the vertices A, B and C.

27 3. We can also say how far the shape must move in a certain direction, which we can specify as a compass bearing. This says how many degrees (navigators normally use three figures) clockwise we turn from due north. Refer to the figure. You can see that east is at 090 and west is at 270. The line is at approximately 200. The triangle above is 5 units away on a bearing of 090. In other words, if you are at the top vertex of the triangle, you can see the new position of the top vertex 5 units away if you look east. Use distance and bearing to translate the parallelogram above. Give the shapes below (A to E) their proper names, label their vertices, and then draw them on this grid, translated to their new positions according to the descriptions below. Finally label the new vertices properly. Hint: work in pencil until you are sure! A 21 units right and 3 units down B 11 units on a bearing of 090 C 20 units left and 6 units down D (31 ; 4) (11 ; 6), (34 ; 4) (14 ; 6), (31 ; 1) (11 ; 3) and (34 ; 1) (14 ; 3) E 7 units on a bearing of 270 followed by 4 units on a bearing of 180

28 Problem Not mastered Partly mastered Adequately mastered Excellently mastered Naming shapes Describing translations in words Using coordinate mapping to describe translations Labelling vertices Using distance & bearing to describe translations Translating from description Translating from distance & bearing Translating from mapped coordinates LO 3.2 LO 3.7

29 ... ACTIVITY 3.2 To understand and apply reflection LO 3.2 LO 3.7 TRANSFORMATION THROUGH REFLECTION Look again at the last problem (E) in the previous section. Can you see that it actually gives us two translations, one after the other? The descriptions for A and C do the same! This will happen again, as it is often the simplest way to describe a complicated transformation of a shape. First plot the following points on the given Cartesian plane, connect them in order with straight lines to draw the shape, and then map the coordinates as given to transform the figures. A(2 ; 2), B(2 ; 4), C(4 ; 4), D(4 ; 6), E(6 ; 6), D(6 ; 2), A(2 ; 2) A(2 ; 2) A (12 ; 2), B(2 ; 4) B (12 ; 4), C(4 ; 4) C (10 ; 4), D(4 ; 6) D (10 ; 6), E(6 ; 6) E (8 ; 6), D(6 ; 2) D (8 ; 2). Can you see that the shape is reflected in the line on the grid? This means that if you were to fold the grid on the line, then the shape will fall on (coincide with) its reflection. In other words, the line of reflection is a line of symmetry for the shape and its reflection. We can also say we are flipping the shape, but this doesn t tell us where it ends up. We could say: Flip the shape to the right and then move it two units to the right. The parallelogram has also been transformed by reflection. Draw the line of reflection. Draw the line of reflection for the circle. The circle can also be seen as having been slid. Describe in words how the circle was translated. What is it about the circle that makes it possible to see its transformation as either reflection or translation?

30 Choose one of the shapes above and connect each point of the shape with its corresponding reflected point. Now take the centres of these lines and draw a line through the centres. This is the line of reflection. Find the line of reflection in this way for all three shapes above. On the grid below, draw the position of each shape once it has been reflected in the given line. Note that the line of reflection can go through the figure; it can touch the figure, or be outside it. We often reflect figures in the x axis or the y axis. On the following Cartesian plane reflect each shape in the x axis, then in the y axis and again in the x axis, so that you have four of them, each in a different quadrant. You may colour the design in. How well did you handle reflections? Quality of work LO 3.2 LO 3.7

31 ... ACTIVITY 3.3 To learn how to transform by rotation, and put translations together LO 3.2 LO 3.7 ROTATION In the diagram below, there is a point marked X on each shape. Imagine that the shaded shape was cut out and loose. A pin was stuck into the point X, and the shape was turned around the pin so that it fell over the unshaded shape. To specify how far we have to turn it, we have to use angles. For example, the triangle was turned (rotated) clockwise through 90. For each of the other shapes, say how many degrees, in which direction, it was rotated. Label the vertices of each of the three figures and describe each of the transformations in terms of coordinate mapping. Describe the transformation of the square as a translation (a) in terms of bearing and direction and (b) in words. Describe the transformation of the square as a reflection. Below you have been given figure A. Draw figure B by reflecting figure A in the given line. Draw figure C by translating figure B 8 units right and 2 units down. Then rotate figure C 180 around the point marked X in figure A to give figure D. We can say that figure D is a complex transformation of figure A, as we needed several steps to draw it.

32 ... ACTIVITY 3.4 To enjoy transformations in the form of tilings and tessellations LO 3.2 LO 3.7 The most remarkable and widely spread use of tessellations can be found in the decoration applied to buildings in the Islamic world. Islam forbids the making of images, so the builders concentrated on shapes. The Persians were competent mathematicians, and this helped to establish the rules of tessellation they used to such brilliant effect in the mosques and other important cultural centres. Even more interesting is the fact that the surfaces were often curved, not flat, which makes the principles of tessellation even trickier. When you can make tiles of a certain shape with the property that you can place them next to each other on a surface so that they don t overlap, and don t leave any gaps, then we call this a tessellation. You can experiment with this by cutting shapes carefully out of cardboard, and fitting them together. You can also do this as a drawing on paper, by combining the principles of transformation (translation, reflection and rotation) to a starting shape until you have tessellated the surface completely. The shapes can be simple, without any transformation except translation, or complicated with complex transformations. When you use more than one shape in a tessellation, you can produce some very beautiful designs. Below you can see a few tessellations. Discuss (in your group) what you see and then try to write down exactly what was done to each shape (translation, reflection and rotation), to produce the final result. Complete any incomplete ones.

33 How much did you enjoy the tessellations? Enjoyment " # $ % LO 3.2 LO 3.7

34 L EARNING UNIT 3 Transformations I can... ASS NOW I HAVE TO... transform figures through translation transform figures by reflection 3.2; 3.7 transform figures by rotation 3.2; 3.7 use appropriate descriptive notation use transformations in tessellations For this learning unit I... ASSESSMENT 3.2; ; ; 3.7 worked very hard yes no did not do my best yes no good partly not good did very little work yes no Date: Learner can... ASS comments transform figures through translation 3.2; transform figures by reflection 3.2; transform figures by rotation 3.2; use appropriate descriptive notation 3.2; use transformations in tessellations 3.2; CRITICAL OUTCOMES Appreciates the power of transformations Works with accuracy and care Works with group partners Applies creativity to mathematics Educator: Signature: Date: Feedback from parents: Signature: Date: